Syringes are widely used to inject drugs into a human body. Korean Patent No. 10-2010-0136245 discloses “Automatic injection gun”. Further, Korean Patent No. 10-2012-0044612 discloses “Skin treatment module”. However, the related art requires the practitioner to repeat the process of inserting a needle, operating a switch to inject the drug, and removing the needles several times, thus rapidly increasing the practitioner's fatigue as the treatment continues. Further, the injection apparatus that automatically injects drug causes a considerable amount of drug loss when the practitioner has a low proficiency level.